Clinical laboratory testing has changed and improved remarkably over the past 70 years. Initially, tests or assays were performed manually, and generally utilized large quantities of serum, blood or other materials/body fluids. As mechanical technology developed in the industrial work place, similar technology was introduced into the clinical laboratory. With the introduction of new technology, methodologies were also improved in an effort to improve the quality of the results produced by the individual instruments, and to minimize the amount of specimen required to perform each test.
More recently, instruments have been developed to increase the efficiency of testing procedures by reducing turnaround time and decreasing the volumes necessary to perform various assays. Present directions in laboratory testing focus on cost containment procedures and instrumentation. Laboratory automation is one area in which cost containment procedures are currently being explored. Robotic engineering has evolved to such a degree that various types of robots have been applied in the clinical laboratory setting.
The main focus of prior art laboratory automation relies on the implementation of conveyor systems to connect areas of a clinical laboratory. Known conveyor systems in the laboratory setting utilize separate conveyor segments to move specimens from a processing station to a specific laboratory workstation. In order to obtain cost savings, the specimens are sorted manually, and test tubes carrying the specimens are grouped in a carrier rack to be conveyed to a single specific location. In this way, a carrier will move a group of 5-20 specimens from a processing location to a specific workstation for the performance of a single test on each of the specimens within the carrier rack.
With the advent of the inventor's new laboratory automation system as described is in co-pending patent application Ser. No. 07/997,281, entitled "METHOD FOR AUTOMATIC TESTING OF LABORATORY SPECIMENS", the inventor has provided a laboratory automation system which requires a different type of specimen carrier. Because the new laboratory automation system of the co-pending patent application calls for identification and conveyance of an individual patient's specimens throughout the laboratory system, it is no longer feasible to utilize conventional specimen tube carrier racks.
Conventional specimen tube carrier racks suffer several drawbacks when considering use in the inventor's new laboratory automation system. First, prior art carrier racks were designed to hold a single type of specimen tube within a rack. Thus, more than one rack would be required for different sizes and types of specimen tubes.
Also, it was not possible to identify the specimen rack and correlate specific test tubes with an individual rack, for independent conveyance throughout a laboratory system.
While the specimen carrier of applicant's U.S. Pat. No. 5,417,922 solved many of these problems, other drawbacks were yet to be addressed. One unaddressed problem was discovered in actual use, where it was found that the weight of a single large test tube at one end of the carrier would be unstable, and liable to fall over while on the conveyor.
Yet another problem of specimen carriers in general was the potential for leakage of fluid in the event of a cracked or broken test tube within the carrier. Spillage of such fluid could easily contaminate the conveyor system as well as persons coming into contact with the specimen carrier.
In the formation of plastic carriers, it was found difficult to achieve appropriate diameter holes for the test tubes, due to shrinkage during heating and cooling processes. Thus, a test tube would either rattle within a hole or the hole would be too small in diameter to easily accept the desired test tube.
The inventors laboratory automation system also incorporates an identification code printed on a label placed on the front surface of the carrier. It was found that, during use, this label was susceptible to tearing or getting caught in various equipment as the carrier traveled along a conveyor. Thus, the label could potentially be damaged to an extent that it was unreadable, and therefore prevent identification of the specimen in the carrier.
Finally, conventional specimen carriers were not capable of retaining a specimen slide.